Water supply valves take many forms, including water supply valves having a “left-side” handle and water supply valves having a “right-side” handle. In some installations, a plumber will typically install a right-side handled water supply valve on the left (hot water) side and a left-side handled water supply valve on the right (cold water) side so that both handles are adjacent one another.
A problem arises where while installing the water supply valves the plumber realizes that he/she has two “left-side” valves or two “right-side” valves, resulting in the plumber needing to obtain (whether it be from the plumber's work vehicle, a storage location, or a supplier) the “other” sided valve to correctly proceed with the installation.